Friction stir additive manufacturing devices and methods for forming in-situ rivets

Abstract

A method of joining a first work-piece to a second work-piece is provided. Each of the first work-piece and the second work-piece include a top surface, an opposed bottom surface, and a side surface connecting the top surface and the opposed bottom surface. In one aspect, the method includes positioning the side surface of the first work-piece adjacent to the side surface of the second work-piece, and advancing a friction stir additive manufacturing tool across the top surface of the first work-piece and the top surface of the second work-piece along a weld line between the first work-piece and the second work-piece. As the friction stir additive manufacturing tool advances along the weld line, a filler material is deposited along the weld line and into a plurality of through holes formed in either or both of the first work-piece and the second work-piece. Each of the plurality of through holes includes a first opening on the top surface, a second opening on the opposed bottom surface, and a passageway through the work-piece between the first opening and the second opening. The method further includes joining the first work-piece and the second work-piece together.

What is claimed is: 
     
       1. A method of joining a first work-piece to a second work-piece, each of the first work-piece and the second work-piece comprising a top surface, an opposed bottom surface, and a side surface connecting the top surface and the opposed bottom surface, the method comprising:
 positioning the side surface of the first work-piece adjacent to the side surface of the second work-piece; 
 advancing a friction stir additive manufacturing tool across the top surface of the first work-piece and the top surface of the second work-piece along a weld line between the first work-piece and the second work-piece; 
 as the friction stir additive manufacturing tool advances along the weld line, depositing a filler material along the weld line and into a plurality of through holes formed in either or both of the first work-piece and the second work-piece, each of the plurality of through holes comprising a first opening on the top surface, a second opening on the opposed bottom surface, and a passageway through the work-piece between the first opening and the second opening; and 
 joining the first work-piece and the second work-piece together. 
 
     
     
       2. The method of  claim 1 , wherein positioning the side surface of the first work-piece adjacent to the side surface of the second work-piece comprises positioning the side surface of the first work-piece in direct contact with the side surface of the second work-piece. 
     
     
       3. The method of  claim 1 , wherein positioning the side surface of the first work-piece adjacent to the side surface of the second work-piece comprises positioning the side surface of the first work-piece in indirect contact with the side surface of the second work-piece. 
     
     
       4. The method of  claim 1 , wherein positioning the side surface of the first work-piece adjacent to the side surface of the second work-piece comprises positioning the side surface of the first work-piece spaced a distance from the side surface of the second work-piece. 
     
     
       5. The method of  claim 1 , wherein, prior to advancing the friction stir additive manufacturing tool across the top surface of the first work-piece and the top surface of the second work-piece, a stiffener is positioned between the side surface of the first work-piece and the side surface of the second work-piece, wherein depositing the filler material along the weld line comprises depositing the filler material between the first work-piece, the stiffener, and the second work-piece, and wherein joining the first work-piece and the second work-piece comprises joining the first work-piece, the stiffener, and the second work-piece together. 
     
     
       6. The method of  claim 1 , wherein the opposed bottom surface of the first work-piece and the opposed bottom surface of the second work-piece are positioned above a mold defining a cavity, and wherein depositing the filler material along the weld line comprises depositing the filler material into the cavity to form a stiffener. 
     
     
       7. The method of  claim 1 , wherein the first work-piece and second work-piece comprise a plurality of through holes. 
     
     
       8. The method of  claim 1 , wherein each of the plurality of through holes extend along an axis generally parallel to and offset a distance from the weld line. 
     
     
       9. The method of  claim 1 , wherein the first work-piece comprises a first material and the second work-piece comprises a second material different than the first material. 
     
     
       10. The method of  claim 9 , wherein the filler material is the same as one of the first material and the second material. 
     
     
       11. An article of manufacture comprising:
 a first work-piece and a second work-piece, each of the first work-piece and the second work-piece comprising a top surface, an opposed bottom surface, and a side surface connecting the top surface and the opposed bottom surface, 
 either or both of the first work-piece and the second work-piece comprising a plurality of through holes, each of the plurality of through holes comprising a first opening on the top surface, a second opening on the opposed bottom surface, and a passageway through the work-piece between the first opening and the second opening, the side surface of the first work-piece positioned adjacent to the side surface of the second work-piece; and 
 filler material deposited across the top surface of the first work-piece and the top surface of the second work-piece by a friction stir additive manufacturing tool, the filler material deposited along a weld line between the first work-piece and the second work-piece and into the plurality of through holes formed in either or both of the first work-piece and the second work-piece. 
 
     
     
       12. The article of manufacture of  claim 11 , wherein the side surface of the first work-piece is positioned in direct contact with the side surface of the second work-piece. 
     
     
       13. The article of manufacture of  claim 11 , wherein the side surface of the first work-piece is positioned in indirect contact with the side surface of the second work-piece. 
     
     
       14. The article of manufacture of  claim 11 , wherein the side surface of the first work-piece is spaced a distance from the side surface of the second work-piece. 
     
     
       15. The article of manufacture of  claim 11 , further comprising a preformed stiffener positioned between the side surface of the first work-piece and the side surface of the second work-piece, wherein the filler material is deposited between the first work-piece, the preformed stiffener, and the second work-piece. 
     
     
       16. The article of manufacture of  claim 11 , further comprising a stiffener positioned between the side surface of the first work-piece and the side surface of the second work-piece, wherein the stiffener comprises filler material that was deposited along the weld line by the friction stir additive manufacturing tool. 
     
     
       17. The article of manufacture of  claim 11 , wherein the first work-piece and second work-piece comprise a plurality of through holes. 
     
     
       18. The article of manufacture of  claim 11 , wherein each of the plurality of through holes extend along an axis generally parallel to and offset a distance from the weld line. 
     
     
       19. The article of manufacture of  claim 11 , wherein the first work-piece comprises a first material and the second work-piece comprises a second material different than the first material. 
     
     
       20. The article of manufacture of  claim 19 , wherein the filler material is the same as one of the first material and the second material.